Cradle of fertility lies in the brain

Washington: Researchers have found the final piece in the puzzle of understanding how the brain circuitry vital to normal fertility in humans and other mammals operates.

Scientists at New Zealand's University of Otago discovered the key cellular location of signalling between a small protein known as kisspeptin and its receptor, called Gpr54.

Kisspeptin had earlier been found to be crucial for fertility in humans, and in a subsequent major breakthrough Professor Herbison showed that this molecule was also vital for ovulation to occur.

Otago neuroscientist Professor Allan Herbison and colleagues at Otago and Heidelberg University, Germany, provide conclusive evidence that the kisspeptin-Gpr54 signalling occurs in a small population of nerve cells in the brain called gonadotropin-releasing hormone (GnRH) neurons.

Using state-of-the-art techniques, the researchers studied mice that lacked Gpr54 receptors in only their GnRH neurons and found that these did not undergo puberty and were infertile. They then showed that infertile mice could be rescued back to completely normal fertility by inserting the Gpr54 gene into just the GnRH neurons.

Professor Herbison said the findings represent a substantial step forward in enabling new treatments for in fertility and new classes of contraceptives to be developed.

"Our new understanding of the exact mechanism by which kisspeptin acts as a master controller of reproduction is an exciting breakthrough which opens up avenues for tackling what is often a very heart-breaking health issue. Through detailing this mechanism we now have a key chemical switch to which drugs can be precisely targeted," Herbison said.